I need help with a pot problem.

[Harderror]

I recently modded my SI T-Amp. I reboxed and did the Stealth mod to the input caps using 4.7 uF caps and a 100k Alps Pot. I also put a 1000 uF cap on the onboard power tap. It sounds fantastic, but, there is a small problem. When I turn the pot, down (from max) it sounds fine until about half way. After halfway down, the left channel drops in intensity and the right channel stays at the level it is at half volume. Once I turnthe pot all the way down, there is no sound in the left channel and there i still sound (not very loud) coming from the right channel. I have been trying to figure out where I made a mistake and am at a loss. Any help would be greatly appreciated.

Tom

[Ebola]

Could be that some solderings of the pot are'nt good.

[Pano]

Originally posted by Harderror
I need help with a pot problem.

Just say NO! Or don't inhale.


OK, sounds like a grounding problem on the right channel. Check your solders and connections as suggested above.

[Harderror]

But no one believed me.!

Anyway, it ended up being a stupid error on my part (as they always are) I went back and looked at the pot and saw that I had not connected the jumper from back pin to front. I put the jumper in (it is a ground jumper) and all problems ceased.

On another note, since I am posting, maybe someone will read and have ideas. I want to make an anti-thump circuit. Relays, from what I have read are notoriously unreliable for this purpose. I suppose I could have a seperate switch for the speakers but that seems like a pain. On the DIYPARADISE site I saw the 3-way toggle method with the 220 ohm resistor. However, I can't seem to find a three way toggle. Ok, regardless, I suppose I can deal with another switch in the mix. So, should I put that switch on power and have a 220 ohm resistor to soft start the amp? Or, should I just switch the ground on the speakers? If I do the former, will it work like the 3 way toggle? Can I have one switch with power and a resistor and then flip another switch with full power without doing damage to the chip? I of course would then flip the switch for soft start off. Hmm. I just can't decide. Any input would be appreciated.

Tom

Here is a picture of her. Probably the ugliest t-amp around but I find her kind of sexy.

[Harderror]

And a shot of her underthings.

[audio1st]

Hello Tom,
The easiest way to cut down the turn-on thump, is to change the 4.7uf input caps to 2.2uf. Bass shouldn't be affected by this...
Give it a try, it will be a lot easier than anything else..

[Harderror]

I had 2.2s in there. I replaced them with the 4.7s because with the 2.2 you begin the downward slope at 40 Hz. I wanted to hit 20 without problems. Therefore I need to figure out the thump issue. BTW I don't run a seperate sub. I run a full range 8" 96 DB sensitive driver that hits 30 Hz. Thanks for the input though!

Tom

[Pano]

Originally posted by Harderror
<snip> with the 2.2 you begin the downward slope at 40 Hz.

You do? How do you figure that? 2.2uF should put the pole at about 4Hz, not 40 - AFAIK.

[Harderror]

Hmm, I must have done my numbers wrong. oops. hehe

So, that being the case, what is the advantage of 4.7? It definitely sounds different. The bass is more solid and the mids seem thicker as well. Any thoughts?

Tom